Pressure vessel



June 11, 1946- J. w. OVERBEKE PRESSURE VESSEL Filed Dec.

w m m m Patented June 11, 1946 PRESSURE VESSEL John William Overbeke, New York, N. Y., assignor to Simmonds Aerocessories, Inc. of New York, New York, N. Y., a corporation of New York Application December 30, 1943, Serial No. 516,167

3 Claims. 1

This invention relates to pressure vessels such as accumulators and surge relievers of the kind used in aircraft, boats and other installations wherein a. fluid is stored or pumped under pressure, and in its more particular applications the invention relates to those forms of pressure accumulators wherein a noncompressible fluid such as oil and compressible fluid such as air are charged under pressure in a shell where they are separated by a flexible membrane.

General objects of the invention are to provide pressure vessels of the mentioned types having improved features of construction leading 'to.

better performance, easier manufacture, and readier assembly and disassembly.

More specifically, objects of the invention are to provide flexible membrane equipped pressure accumulators having a wide mouth allowing ready interior access to the preferably seamless shell construction, coupled with means for effectively holding the membrane and sealing the wide mouthed end against the heavy fluid pressures employed.

Further objects are to provide pressure accumulators having a novel membrane or bag clamping and end sealing means which, as a safety precaution, cannot be loosened or disassembled while the accumulator is under pressure, but, which,

after this pressure has been properly dispelled, is capable of very easy and rapid disassembly and assembly, without the need for any special tools to fit the bag into the shell or to tighten the parts. 7

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth, and the scope of which invention will be indicated in the claims. 1

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawing, in Which:'

Fig. 1 is a vertical sectional view through a pressure accumulator embodying features of the invention; and

Fig. 2 is a fragmentary plan view of the accumulator shown in Fi 1, part being broken away to show the underlying construction.

Referring more particularly to the drawing, there is shown a pressure accumulator having a shell ID, the interior of which is divided by a 2 membrance I i into a liquid compartment l2 and gas compartment l3. The shell may be any suitable shape such as ovate or spherical, as shown, and is preferably formed of steel. At one end it has a. neckcomprising a wide mouth l4 and a collar l5 having a central opening of less diam-- eter than the mouth whereby it has a shoulder facing the interior of the shell. The mouth has a series of integral lugs l1 disposed around its outside, and the collar has a corresponding number of spaced hooks I8 adapted to fit under these lugs and hold the collar against outward movement under pressure within the shell. The hooks l8 may be fitted between the lugs I 1 and slid therepast after which a slight axial turn will lock the collar beneath the lugs in the manner of a breech or bayonet lock.

The central opening of the collar has a stopper l 9 slidably fitted therein, from below, there preferably being a sealing ring 20 between these parts. At its lower end stopper l9 has an outwardly extending flange 2| underlying the interiorl facing shoulder l6. Between these isdisposed the edge 22 of the membrane H, which membrane in the form shown is of bag-like construction and made of elastic rubber or rubberlike material. The particular shape of'the bag or other membrane used will depend'in part on the type and size of shell used, being in the present instance illustrated as a generally spherical bag occupying much of the shell interior when inert and adapted when fully expanded substantially completely to occupy the space within the shell.

The bag edge 22 is adapted to be squeezed tightly between the stopper flange 22 and the collar shoulder l6 and these parts are shaped and dimensioned, and the bag edge is preferably thickened, in order that the rubber stock may be pressed and laterally displaced tightly against both the shell mouth 14 and the collar shoulder IS, in forming a seal which tightens under the system pressure within the accumulator. A further sealing ring 22 is preferably disposed between the shell mouth and thecollar although the main sealing is effected by the compressed bag edge. Such seal 22 as well as seal 20, while desirable, is not regarded as being essential.

The stopper l9 preferably has an air passage therethrough in which is fitted an air introducing back check valve generally designated 23, which may be of known or suitable construction permitting release of air from the bag II when wanted. The stopper 19 also carries a lock nut 24 threaded to its outer end. The purpose of this nut is primarily to prevent the stopper from dropping inwardly through the collar rather than to tighten the seal against the bag edge. This latter seal is eflected by pressure within the shell which acts against the interior face of the stopper and tends to force it outwardly in the manner of a piston through the central opening in the collar IS. The parts are sufllciently tightly assembled so that actual movement under the urge of this interior shell pressure is quite small. and if desired such movement may be arrested by an additional abutment 25 on the inner side of the collar.

At the threaded oil passing fitted and fastened an oil si n- In assembly, the membrane may be inserted within the shell before or after the oil plug 21 is attached. The bag edges 22 are laid over the stopper flange 2| after which the collar I is hooked into place. The lock nut 24 is then screwed on and tightened sufiiciently to prevent loose play among the stopper, colla and membrane parts. The accumulator may then be insorted in a suitable hydraulic pressure system. Operating pressures within an aircraft system of the kinds contemplated run quite high, one widely used illustrative system ranging from six hundred p. s. i. when the accumulator bag is fully expanded, to fifteen hundred p. s. i. when the accumulator shell is normally charged with oil. It will be seen that the force exerted against other end the shell has an outwardly opening 26 into which is plug 21 of known dethe stopper and consequently active in sealing the neck, is quite high, and that the parts are of simple rugged construction especially suited to withstand the forces imposed. The lock nut l4, collar l5, and shell III are preferably held against undesired relative turning by a suitable locking wire (not shown) strung among these parts.

\ It will be noted that the bag and the parts I! and is forming a closure for the shell mouth and for the bag. are in effect a unit capable of assembly with the shell, the bag being attached to the closure means forthe shell.

.When the accumulator is under operating pressure' and the collar I5 is hooked in placethe parts are held together so firmly that they cannot be separated until interior pressure is relieved. This circumvents one possible cause of accidents ob.-

taining withthe accumulators heretofore in use,

which were sometimes inadvertently opened before the interior pressure had been safelyreduced.

The shell construction provided by the present arrangement of parts is well suited to be formed. from steel stock drawn to seamless cup shape and then spun "to the wide mouthed shape shown. Also, by virtue of the wide mouthed construction at one end, the interior of the shell may be smoothly finished by known bufllng or polishing tools, access for which is provided by such mouth. If desired, an extra smooth mirror finish may be obtained by chrome-plating the shell interior before polishing, since the mouth permits entry of plating electrodes. Such a smooth interior is desirable to prevent harm to the bag which is pressed thereagainst with considerable force at I times. No special tools are required to assemble or disassemble the bag and shell, or the remaining accumulator parts, which is of advantage cspecially when making repairs or replacements in the field.

Features of the invention may be used to advantage in accumulators or surge relievers whether or not the fluids employed are air and oil, and certain aspects and features of the described closure means are generally useful in pressure vessels of all kinds, whether of the accumulator .or other types.

Since certain changes may be made in the above construction and diflerent embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing .shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims, are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A pressure accumulator corprlsing; a shell having a fluid passage at one end and a wide mouth at the other end, a collar having a central opening of less size than said mouth fastened thereto, a flexible membrane separating the interior of said shell into two chambers, a stopper outwardly slidable in said collar opening and I having an outwardly extending'lower flange facing an interiorly facing surface of said collar, said membranehaving its edges clamped between said stopper flange and collar surface under pressure obtaining within, said shell.

2. 'In a pressure vessel, a shell having a mouth collar against its holding means under pressures within said shell.

3. In a pressure accumulator, a shell having a mouth at one end, a collar disposed acrosssaid mouth and having a central opening smaller than said mouth, holding means between-said shell and collar restraining the latter against outward movement from said mouth, an outwardly movable stopper, a flexible pressure bag within said shell having its edges held between said stopper andcollar, said stopper acting to squeeze said bag edges against said collar in response to-pressure within said bag, and a limiting abutment between said'stopper and collar serving to prevent undue crushing of'saidbag edges therebetween.

' JOHN WILLIAM OVERBEKE. 

